Meeting Details

Consider a (discrete) dynamical system F(x, y, z) := ( f(x), g(y), h(z) ) for polynomials f, g, and h, acting on the three-dimensional space over complex numbers. What subsets S are invariant under F, in the sense that F(S) is a subset of S? In particular, what algebraic sets, that is solution sets of systems of polynomial equations, are invariant under F? I will describe the tools from modern model theory, a branch of mathematical logic, that reduce this question to understanding composition of one-variable polynomials, and an old theorem of Ritt that supplies this understanding.